CA1185724A - Highly filled thermoplastic compositions based on ethylene interpolymers and processing oils - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
Highly filled thermoplastic compositions use-ful as sound-deadening sheeting for automotive carpet are obtained by blending about 5-50% by weight of an ethylene interpolymer, such as ethylene/vinyl ester, ethylene/unsaturated mono- or dicarboxylic acids or esters of said unsaturated acids, etc., about 2- 15% by weight of processing oil; and about 50-90% by weight of filler.

Description

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TITLE
Highly Filled Thermoplastic Compositions Based on Ethylene Interpolymers and Processing Oils BACKGROUND OF THE INVE2~TION
Field of the Invention This invention relates to highly filled blends and more specifically, it relates to highly ~illed blends of ethylene interpolymers modified with processing oil.
~ 1~____ o e Prior Art The use of processing oils with natural rubber or synthe~ic rubber-like compounds con~aining sulfur, accelerators, carbon black and other additives customarily used in the rubber industry is well known. In some instanc2s in order to ob~ain very high tensile strength values, fillers are omitted~ On the other hand, it is known that styrene/butadiene rubber (SBR) compounds, such as are used to adhere jute secondary backings to carpets, can readily hold up to 80~ by weight or more of calcium carbonate filler. Vulcanization or curing enhances blend ~trength.
For thermoplastic elastomeric uses it is desirable both to avoid curing and to employ fillers to reduce blend costs, as well as to increase blend density.
Binary blends of ethylene/vinyl acetate (EVA) copolymer with filler are known as articles of commerce.
The practical limit for addition of a filler such as the more commonly employed medium density fillers, edg.
CaCO3, bauxite, gypsum, e~c., is about 60% by weight, even when using a relatively low melt index (higher molecular weight) resin, or softer, higher vinyl acetate grades. As filler le~els rise, other properties suffer, such as melt index (as it drops, extruder pressures mount rapidly), softness (the "hand" becomes much stiffer), and elongation (which drops alarmingly). Ultimately, at about the 70~ filler level, it is not possible to compound binary EV~/Whiting ~naturally occurring ground limestone~
CaCO3, from Georgia Marble Company) blends as the mixture , `~

will no longer "flux" in a Banbury*Mixer (the charge merely stirs- the resin will not "work" as the blades tuxn, no power rise ensues, the mixture on discharge is still discrete EVA pellets ln a powdery Whiting mass).
If one were to use a very dense filler, such as BaS04, approximately 10~ by weight more filler can be added to binary EVA blends.
Industrial noise and its control are items of incxeasing concern to governmental, environmental, and industrial organizationsO Governmental agencies are establishing noise limits to which workers may be exposed to protect their health.
From an aesthetic standpoint, noise also presents problems. Advertisements for "quie~ riding" automobiles axe ubi~uitous. Manufacturers are attempting to make other vehi.cles quiet as well--including campers, trailers, buses, trucks, and off-road-use farm vehicles.
It has long been known that interposing mass between a sound source and the area to be kept quiet is an effective means for attaining sound deadening. A
stone wall is extremely effective~-but is no~ often practical. A sheet of lead is thin, flexible, often highly e~fective, but costly. The challenge, ~hen, is to attain a dense, thin, flexible sheet which can be interposed between a source of noise and the area to be quietened.
Sheets of thermoplastics or of rubberlike materials have long been used as sound-deadening means.
To make the sheets flexible, dense, strong t and inexpen-sive has posed a challenge ~o compounders for many years.For some uses, such as automobile carpet underlayment, the sound deadening sheet must also be moldable.
Schwartz U.S. Patent 3,904,45b is related to a me~hod ~or inhibiting transmission of airborne noise by interpocing in the air space between the noise source an~ the locatio~ to be insulated a thin, dense normally sel~-supporting film or sheet composed essentially of * Penotes trade marlc ;7~

from about 10 to about 40% by weight o~ ethylene/vinyl acetate copolymer having an average vinyl acetate content of from about 10 to about 42% by weight and a glass transitlon temper~ture of at least abou~ 30C below the average ambient temperature in the air space, and from about 60 to about 90% by weight of inorganic filler materials, such as sulfates, carbonates, oxides, etc.
of barium, calcium, ca~mium, etc., ef~ective tO
density greater ~han at least 2 grams per cubic centimeter.
EVA copolymers have been used industrially for nearly two decades, however, they are not known to be used in conjunction with processing oils as articles of commerce. This could well be an outgrowth of the way EV~ commercialization has proceeded. That is, most EVA
blends are based on EVA/paraffin wax tec~nology, where paraffin wax weight is often up to ten~times the weight the EVA present. Furthermore, despite the obvious savings inherent in using lower-cost, iower-quality waxes, ~uch as scale wax or slack wax, all a~tempts to do this have failed. The reason was always the same--the oil content of the wax migrated and destroyed the effective-ness of the coating or adhesive when the oil reached the bond or sheet surface. Thus, compounders "knew" that oil could not be used in EVA blends and technology developed along other lines.
Rundle U.S. Patent 3~497,375 discloses coating compositions for wooden concrete molds consisting of ethylene/vinyl acetate copolymer and paraffinic oil.
There is no filler employed in the coatlng compositions of this patent.
Monaghan U. S ~ 3,379,193 discloses teeth cover~
made of ethylene/vinyl acetate copolymer in itself or in combination wi~h mineral oil and, if desired, with fib2rs and coloring materials. The preferred formulation is disclosed to be 47~ by weight of ethylene~vinyl acetate copoly~er, 47% by weigh~ of mineral oil, 5~ by weight of nylon fibers, and 1~ by weight of titanium dioxide.

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German Patent Applica~ion No. 2,319,431 of R~
Nowell et al, published 1973 October 31 discloses sound deadening composites suitable for use in automobiles which consist of a highly filled polymer sheet (for example, 300-1200 or even up to 1500 parts of filler per 100 parts of polymer) which on its backside is provided with a filler material sheet, e.g., a polymer foam. Suitable polymers for use are disclosed to be terpolymers of ethylene, propylene and a non-conjugated diene (EPDM), polyvinyl chloride (PVC), mixed polymers of e~hylene and vinyl acetate (EVA), styrene-butadiene mixed polymers ~SBR~ and mixtures of these materials with thermoplastic polymers, such as polystyxene and poly-olefins.
Boyer U~S. 3,010,899 discloses blends of ethylene/vinyl acetate resin and mineral oil which are either rubbery or grease like depending upon the pro-portion of oil to resin and can be used as a substitute or crepe rubber or as a grease. It is further disclosed that fillers such as carbon black or finely divided clays ~0 can be added to the rubbery products to increase hardness and produce materials suitable as floor tile. As indicated for ~xample in Claim 11, the filler, carbon black t iS
pxesent in a "minor amount" while the oil-ethylene/vinyl acetate copolymer mixture is present in a "major amount".
In Example 2 an oil-~resin/carbon black ratio of 4 parts by weight to 1 part by weight is indicated.
Rosenfelder U.S. Patent 3,203,921 discloses the use of compositions consisting essentially of 73-88%
by weight of a homo- or copolymer of ethylene (which can be ethylene/vinyl acetate or ethylene/e~hyl acrylate copolymer), 2-7% by weight of an aliphatic paraffinic hydrocarbon mineral oil and 10-20% by weight of a mineral filler, (for example, calcium carbonate, barium sulfate, etc.) for preparing blow-molded objects such ~s dolls.
SUMMARY OF T~E INVENTION
.. ...
According to the present invention there is provided a composition consisting essentially of (a) from about 5 to 50~ by wei~ht of at least one copolymer of ethylene with at least one comonomer selec-ted from the group consisting of vinyl esters of saturated carboxylic acids wherein the acid moiety has up to 4 carbon atoms, unsaturated mono~ or dicarboxylic acids of 3 to 5 carbon atoms, the ethylene content of said copolymer being at least about 60% by weight, the comonomer content of said copolymer being from an amount sufficient to provide the desired oil compatibility and blend elongation to about 40~ by weight, and the melt i~dex of said oopolymP-r being -from about 0.1 to about 150, provided that when said copolymer of ethylene is an ethylene/vinyl ester copolymer said copolymer can con-tain up to about 15~ by weight of carbon monoxide; (b) fro~ about 2 to about 15% by weight of processing oili and (c) from about 50 to about 90% by weight of filler.
The present invention also provides a composi-tion consisting essentially of (a) from about 5 to about 50 parts by weight of at least one copolymer of ethylene with at least one comonomer selected from the group consisting of vinyl esters o saturated caxboxylic acids wherein the acid moiety has up to 4 carbon atoms, unsaturated mono-- or dicarboxylic acids of 3 to 5 carbon atoms, and esters of said unsaturated mono- or dicarboxylic acids wherein the alcohol moiety has l to 8 carbon atoms, the ethylene content of said copolymer being at least about 60% by weight, the comonomer content of said copolymer being from an amount sufficient to ~rovide the desired oil compatibility and blend elongation to about 40% by weight, and the melt index of said copolymer being from about 0.1 to about 150, provided that when said copolymPr of ethylene is an ethylene/~inyl ~ster copol~mer said copolymer can contain up to about 15%
by weight of carbon monoxide or sulfur dioxide; (b) ~S'72~

from about 2 to about 15 parts by weight of processing oil; and (c) from about 50 to ~bout 90 parts by weight of filler.
Further according to the present invention, there is provided the above composition wherein the filler has sufficiently fine particle size to enable production of a smooth, continuously extruded sheet, strand, or tube, substantially free of melt fracture and such that when said strand is pelletized it yields pellets that are free flowing.
Further provided according to the present invention are the above com ositions in the form of a sound deadening sheet.
5till further provided according to the present invention are carpets and especially automo-tive carpets having a backside coating consisting essentially of the above compositions.
As used herein the term "consisting essentially of" means that the named ingredients are essential, how-ever, other ingredients which do not prevent theadvanta~es of the present invention from being realized can also be included.

5a D~TAIL~D DESCRIPTION OF T~IE I~VENTION
It has been found that inclusion of a process-ing oil in highly loaded blends o~ ethylene/vinyl acetate and filler allows the preparation of considerably higher filler level containing blends than can be attained in corresponding binary blends of ~VA-filler. E'urther-moret~secomponent blends can be prepared employing high oil content, even in ~he absence of rubbers, elastomers, carbon black, or other oil absorbing materials. If 10 desired, EVA-base~, non-bleeding blends containing very high filler levels can be prepaxed employing certain pro~
cessing oil5 according to the ~resent invention.
The ethylene copolymers suitable for the com-position of the present invention are copolymers with at 15 least one comonomer selected from the group consis~ing OL
vinyl esters of saturated carboxylic acids wherein the acid moiety has up to 4 carbon atoms, unsaturated mono-or dicarboxylic acids of 3 to 5 carbon atoms, and esters o~ said unsaturated mono- or dicarboxylic acids wherein the alcohol moiety has l to 8 carbon atoms. Terpolymers of ethylene and the above comonomers axe also suitable.
In addition terpol~mers of ethylene/~inyl acetate/carbon monoxide containing up to about 15 percent by ~eight o~ carbon monoxide can also be employed.
~5 The ethylene content of the copolymer is at least about 60~ by weight and the comonomer content is from an amount sufficien~ to provide the desired oil compatibility and blend elongation ~o abou~ 40% by weight. Generally from about 60 to about 95~ by wei~ht 30 of ethylene and from about S to about 40~ by weight of comonomer will be suitable. The preferred ethylene and comonomer lev~l is ~rom abou~ 65 ~o about 85~ and rrom about lS to about 35~ by weigh~, respectively. A
mixture of two or more ethylene copolymers can be used in the blends of the present invention in place of a single copolymer as long as the average ~alues for the comonomer content will be wlthin the above-indicated range~
Employing a copolymer containing over 28% non~
ethylenic comonomer (such as vinyl acetate) results in blends that are less stiff and have lower tensile strength r while their elongation is increased. The most preferred level is a}~out 18 to 28 weight percent. Below 18~ vinyl acetate, the blends become much stiffer, lose elongation, and oil compatability problems arise. Even blends made with nonbleeding oils become "oily" as polyethylene homopolymer is approached.
I~lelt index of the copolymer can range from about 0.1 to about lS0, preferably from about 0.1 to about 50.
Physi.cal properties, principally elongation, decline to lower levels when the e~hylene copolymer melt index is above about 30. Lower melt index ranges~ about 1 to 10, are most preferred to maintain strength.
Generall~ fro~about5 to about50~kyweight of ethyl~:le 20 copolymer ise~loyed in thecompositiono~ thepresen~ inven~ion, ~referably fromabout5 to about30%b~ weight,a~dmostpreferably from about 10 to about 25~ by weight.
In accordance with the abov~, suitable ethylene copolymers are such as ethylene/vinyl acetate/ ethylene/
25 acrylic acid, ethylene/methacrylic acid, ethylene/ethyl acrylate, e~hylene/isobutyl acrylate, ethylene/methyl methacrylate, and ethylene/vinyl acetate/carbon monoxide.
Particularly suitable copolymers are ethylene/vinyl ace-tate, and ethylene/ethyl acrylate copolymers.
The oil ingredient of the composition of the present invention is known as processing oil. Three types of pr~cessing oils are known-paraffinic, aromatic and naphthenic. ~one of these are pure, the grades identify the major oil type present.
Paraffinic oils tend to "bleed" from blends~
Bleeding is normally not clesirable, but could be useful in specialty applications, for example, in concrete forms where mold release characteristics are valued.
On the other hand,naphthenic and aromatic oils are non-bleeding when used in proper ra~ios and are thus preferable for uses such as automotive carpe~ backsize.
Processing oils~ are also subdivided ~y viscosit~
range. "Thin" oils can be as low as 100-500 SUS (Saybolt Universal Seconds) at 100F (38C.). "Heavy" oils can be as high as 6000 SUS at 100~F (38C.). Processing oils, especially naphthenic andaromatic oils with viscosity of from about 100 to 6000 SUS at 100F (38C) are preferred.
The amount of oil presen~ in the composition of the present invention i5 from about 2 ~o about 15~
by weight, preferably from about 4 to about 12~ by weight.
Most preferably when using a filler of mec7ium density, such as calciuTn carbonate, the amount of processing oil is from ahout 5 to about 10~ by weight, and when using a filler of higher densit~, such as ba~ium sulfate, the amoun~ of processing oil is from about 4 to aboutl0~ by ~Jeight.
Addition o~ processing oil in an amount of less than about Z% will not have a significant effect.
Processing oil in the amount of in excess of about 10~
will cause the melt index to rise rapidly and the blend to become much softer. At extremes, for example, at 70 filler, over 15% oil and less than 15% EVA, the oil con-tent overwhelms the blend as the amount of EVA Dresent is not adequate to provide "guts" for the blend.
Table I shows the effect of the type of oil selected upon an important property o the final blend;
i.e., does oil exude from the blend or does it stay bound firmly within ~he compound? TableII shows how the oil exudation ratings were arrived at. Table III
su~ari~es t.he composition, pro~erties and origin of various processing oils. In the Table I comparison five aromatic oils were evaluated. All or them stayed fir~ly bound within the compound, even after ~wo weeks of standing. Further, all six paraFfinic cils tested showed a marked tendency to exude within a week under ambient conditions. The test specimens all showed a tendency to exude, all withln a week, and, in some cases, on standing overnight.
The naphthenic oils generally showed no tendency to exude- although in a few cases some exudation ~as noted. Properties of oil~ depend upon two fact~rs--the procesa and conditions used during refining and the source of the crude oil used. As ecamples, Tufflo*
2000 (P) and "Tufflo" 2000 (H) are rated b~ the manu~ac-turer as closely equivalent products. Nevertheless, the (P = Philadelphia) version did not bleed, but blen~s based on the (H - Houston) product shor,led asli~httenden-cy to exude oil. Thus, the purchaser of an oil must evaluate it ~ith care--and must work closely with the refiner to ensure constancy of quality. This is particularly true because industrially obtained process-ing oils are not "pure" in tllat they nearl~
always contain more than one type of oil. For example, an "aromatic" oil contains predominantly aromatic ring structuxes but also usuall~ con~ains substantial pro-portions of naphthenic xings. Similarly, some naphthenic oils contain paraffinic oil as well.
Relative proportional shif~s among the oil types ~ill, of course, change blend performanceO
This is no~ to say that bleeding of oil, per se, is inherently good or bad. For most uses, bleeding is not acceptable and must be avoided. However, in other cases, e.g., a release coating or film intended for application to a concrete mold or form, a migration of traces Or oll could pr~ve desirable ln avolding adhesion Oc the curing concrete to the form.
~ he-comments above apply to smooth ?ressed sheets, mad2 with a high surface sheen, as would be produced in industry b~ a conventional combina.ion of an extruder plus a set of polished rinishing rolls.

* Denotes trade mark The detection of exudation tendency or d~gree is ~uch moxe difficult~ if not i~possible, to observe when sh~ets with roush surfaces are used.

S TABLE I
Exudation Rating As A Function Of Type And Source Of Oil Ingredients: EVA ~3*/EVA ~4*(50/50) - 16~ by wt.
_ Oil to be tested - 9~by ~It.
Fille.r - No. ~r~hitLng* - 75~by wt.
ondition: Two weeks at 72F,50% R.H.
~ .
Oil Exudation Rating Aromatic: Sunde~*790 & 8600T None Flexon**340 & 391 None Tufflo" 431 None Naphthenic: Circosol**450,4240~ 5600 None Sunthan~*450 & 4240 None "Flexon" 676; "Flexon" 766 None; heavy, respectively "Tufflo" 500 and 2000 (P) None "Tufflo" 2000 (H) and 6024 Slight "Tufflo" 6204 Heavy Paraffinic: Sunpa~*150 & 2280 Heavy "~lexon" 815 & 865 Heavy "Tufflo" 60 & 80 Heavy *d~fined in Table IV
**denotes trade mark 1.0 TABLE II
Oil Exudation Ratin~ For Compositions ~bsorption On Rating Visual Tactile Pa~er None No visible Feels dry No ~ransfer to change paper ~er~ No visihle Dry Smallest percep-Slight ch~nge kible oil traces on paper Slight No visible Borderline Oil transfer to change ~aper is easily noticed.
Moderate Surface Slippery Paper beneath gloss changes feel but no sample is note~-may visible definitely wet-look "wet" transfer to under entire sam-fingers ple area.
Heavy Wet film Hea~y film Paper is thoroughly readily exists-which wetted. Oil noticed~oil s~reaks when wicks well beyond droplets may rubbed. Pin- the area in contact be visible ger feels with the test oi.ly after strip.
test.

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Y VISCOSIrYCARBON ATO~IS
p AS~ SUS (2) ~ OL .
TRADE NAME E TYPE SP.GR 100F _lG~F 0~ C~L_~ WT, (3) "CIRCOSOL"
4240 N 103 0.952525 87 21 39 40 39S
"CIRCOSOL"
5600 N 103 0.955945 135 20 38 42 450 10"CIRCOSOL"
450 ~ 103 0.94 515 52 21 37 42 355 "SU~TPAR" .
150 P 104 ~ 0.88 500 64 4 27 69 530 2280 P 104 B 0.892907 155 4 25 71 720 790 A 102 0.98350085.7 37 28 35 375 "SU~DEX" 101 0.98 - 300 30 22 48 "SUNT~ E"
~50 N 103 0.93 502 52 15 43 42 355 "SUNTHANE"
20 4240 ~ 103 0.8~2206 85 18 ~1 41 400 "FLFX0N"
340 ~ 102 0 O 95 130 38.7 31 41 28 "FLEXON"
766 ~ 104 A 0.90 50358.2 1 45 54 "FLEXON "
865 p 104 B 0.87 33243-61 4 27 69 "FLEXO~"
815 P 104 B 0.9026S0 155 2 32 66 "FLE~ON"
676 N 103 0.931200 72 15 40 45 "FLEXON"
391 ~ 102 0.984010 g2 28 43 29 "TT,rFFLO ~1 P - 0.88 600 68 4 26 7~ 550 "TUFFLO"
P 0.902640 155 4 23 73 72 "~UF FLO "
3~500 (4) ~ 0-94 518 5~ 22 36 42 355

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TABLE III(cont'd) CL~SSIFICATION~ D C~L~RACTERISTICS OF PROCESSING OILS
T (l) y VICOSITY CARBON ATO~IS
P ASTM SUS(2~ % ~lO~.
TRA E ~ E TYPE SP.GR lOG~F 21CF C~ C~l ~p WT.(3) "TUFELO"
2000(4~ N 0.9~2150 8220 39 41 390 "TUFFLO"
~l~5) A 0.997060 12840 20 40 425 "T[;FFLO"
lC2000 (5) N 0.932110 97 12 38 50 460 "TUFFLO"
6024 (5) N O.S9 175 43 1 50 ~9 345 "TUFFLO"
6204 N 0.911750 91 2 49 4~

0 (1) A = aromatic; N -n~phthenic P = paraffinic. As classified by supplier t2) SUS = Saybolt Universal Seconds - 5 x Visco5ity in centipoise (cp)

(3) asprovided by su~plier

(4) from Philadelphia

(5) frorn Houston Source of Circosol, Sunpar, Sundex, Sunthane oils ~as Sun Oil So~lrce of Flexon oils -~as Exxon Source of Tufflo oils was ~rco 7Z4~

The third essential ingxedient of the composi-~ion of the present invention is thefiller. The percentage of filler th~t can be included in the com~osition of the present inven~ion on a wei~ht basis is primarily a runction of the density of the filler. Particle size of the filler has a ~inox effect. Fine par~icle size fillers generally havea tendency to result in higher blend viscosities and they are also more expensive. ~9 Whi~ing which has been used extensively in the present com~osl tions (about 95% through 32S mesh) represents a viable midpoint in coarseness, availabilit~ and cost. Most preferred fillers are calcium carbo~ate, a~d barium sulfate. Th~ amount of filler Pr~s~nt in the composition of the present invention is from aboui S~
to abo~t 90% by weight, preferably from about 60 to about 85~ by weight. Mos~ preferablyt when using a filler of medium density, such as calcium carbonate, the amount of filler is from about 65 to about 80% by weight, and when using a filler of higher densi~y, such as barium sulfate, the amou~t of filler is from about 70 to abou~ 85% by weight.
When the ethylene interpolymer employed in the composition of the presen~ invention is an ethylene/vinyl ester copolymex, such as ethylene/vinyl acetate, and 2S ~Jhen the filler em~loyed in combination therewitn is clay, such as SUPREX~ Clay, lt is necessary to add oil to the blend in order to passi~ate ~he clay. Proper se~uencing of the addition of the ingredients is necessary to attain success in the mixing operation. Sequence A
30 ~elowr during int2nsive mixi~g will be suc`cess-ul; while Sequence B may fail, if the EVA/claY mixture is heated before the clay is p~ssivated bec2use of the decom~osi-~ion of the EVA copolymer caused by the clay.
Deoom~osition is accom?anied ~v libe~ation o~ anh~d~ous acetic acid, and discolora~lon o~ the blend.
S~u~nce 3~ Clav - "Y" - Oil ~ lix - EVA ~ Mix.
Se~u2nce B: "X" - Cla~ - EV.~ - Mix - Oil - "Y" - Mix.

*denotes trade mark 14 . . . ...... .. .. .. .. . . .. . . .. ................

In the above illustration, "X" and "Y" may be either nothing or other fillers, diluents or resins that do not influence the otherwise proba~le adverse reaction of the EVA with untreated clay. The abo~e passivation of clay, in order to enable use of substantial amounts of clay in ethylene/vinyl ester blends is the subject ~atter of simultaneously filed patent application Serial ~o. 33~ 898 o~ F. G. Sch~macher.
Polymers, both homo- and co~olymers, other than the ores referred to above, can also be used to some extent in c~mbination with the above specified polymers witho~t significantly interfering with the advantayes obtained by the present invention. Similarly other ingredients can also be added to the compositions of the present invention by a compoundcr in order to obtain some desired eLfect, such as reduction of cost, or enhancement of physical property. Accordingly, extender resins, waxes, foaming agents, antioxidants etc. that are widely used, particularly in hot melts, 2~ can be included in the compositions OL- the present in ~rentiOn .
A comm~rcially sized batch-type Banbury or equivalent intensive mixer is entirely suitable for preparing the compositions of khe present invention. A
Farrel*continuous mixer ("FCM") is also an excellent mixing device. In either instance, dry ingredients are charged in routine fashion. It is convenient in most cases to inject the oil component directly into the mixing chamber of either unit as per widel~ used practice with this type of equipment. A mix cycle of a~ut 3 minutes is generally a~equate for the ~anbury mixer at an operating temperature usually be~ween 325 and 37i~.
The operating rate for the FCM unit generally ~ill fall *denotes trade mark within ranges predicted by literature ~repared by the Farrel Company, Ansonia, Connec~icut. Again, lemperatures between 325 and 375F. are effective. In both cases, a very low oil level, say about 2-3~, may require higher temperatures, while oil levels above about 7% may mix well at lower mixer temperatures~ While not evaluated, i~ is expected that otner devices for compounding of viscous mixes (MI of 0~1 to 20) should be en~irely satisfactor~7--~u-~ in anv case, ~rototype trials in advance axe desirable.
Once blends are mixed, routine com~ercial practices may be used, such as underwater melt cutting plus drying or use of sheeting plus chopping methods, to produce a final pelletized product.
Primary use for the compositions of the present invention will probablybe~n Thesheeting field, particularly for low cost, dense ! sound deadening struc-tures. Outstanding characteristics such as improved "hand", ~drape~, r duced stiffness, and reduced thick-ness of the extruded sheeting result from the compositions o the present invention The blends of the presentinvention can readily be extruded onto a substrate, such as an au~omotive carpet, or can be extruded or calendered as unsupported Eilm or sheet. Depending upon the equipment used, and the compounding techniques employed, it is possible to extrude wide ranges of film thickness, fro~ below 20 mils to above 75 mils. While not demonstrated, a film thickness of even less than 10 mils and ovex 100 mlls could probably be readily attained. This then provides industry with an opportunity to vary the amount of sound deadening to be attained by varying film thickness, density of blends t ratio of filler load to binder, and similar techniques well known in the art The sound-deadening sheet produced may be used in various ways:
When applied to automotive carpet, blends described are an effective and economic means to deaden sound, while also simultaneously serving as a moldable 17 ~ '72 suppor~ ror t~ carpet.
When used in sheet form, the blends can be installed in other areas of an automobile, truck, bus, e~c ., such as side panels, door panels , roofing areas~
S etc.
In sheet form, blends may be used as dxapes or ha~gings to shield or ~o surround a noisy piece of factory equipment such as a loom, a forging press, e~c.
In lami.na~ed sheet form, blends, faced with another material, might be used to achie~-e both a de~orative and a functional use--such as dividing panels in an open-format office.
In the application o. the com~ositions o~ the present invention in carpets, the initial "soft" carpet manufacturing stages--~uftins of loops, cutting them to form a plush if desired, d~eing and drying, and then storing as u~backe~ "soft" roll goods until ready to appl~ a back-coating--are entirely similar to well-known methods as already described in paten~s, e~g.,: S~ahl, U.S.P. 3,645,948.

Inpreparing automotive car~2t backed with a sound-deadeniny sheet, several routes may be used. All are technically feasible~ The most logical routes would be ~1) and (2~ below, although route ~3) would also be ~ractical and might be prefer~ed by one who did not want to invest in extrusion equipment.
Route(l~-prepareanautomotive~type "soft" carpet by tufting, dyeing, and drying followin~ known ~-r~
TAen, using standard extrusion coa~ing ~echnology, 2pply first a relati~ely fluid precoating material such as a high mel~ index EV~ or polye~hylene resin or hot melt blend in an amount sufficient to bin~ the individual bundles as disclosed e.g., in Example III, of the above Stahl patent, and Smedberg U.S.~. 3,684,600. Then to the still warm and still sof~ precoa.ed c~rpet, apoly the desire~ amou~ of sound-deadening hot melt b~e~d 1~

1~
by means of a second extruder. Standard nip roll and chill roll means are used to secure good adhesion of the main coat to the precoat and to the carpet. The thick-ness of the combined layers of hot melt will be selec-ted so as to achieve the desired sound-deadening level, in addition to moldability,.shape retention ~bility, fuzz and pill resistance, etc. as ls required by the ultimate customer.
Route (2)-In place of two extruders, it i5 possible to use a latex precoat, followed by a dxying oven, which then will ul~imately be followed by an extruder to apply the sound-deadening coa~ing. Alternatively, the precoating mëthod taught by Smedberg, U.S.P. 3,684,600, may ~e employed. In either case, the extrusion step can be carried out on an in-line basis~ or, alternately, the sound~deadening coating can be extruded ont~ the c~arpet in a future operation.
Route (3)- The carpet can be made and precoated as per Route (1) or Route (2~ above, and then stored.
Sound-deadening shee~ can be made elsewhere by extrusion or a calendering process in a totall~ independent opera-tion. Then, the sheet can be laminated to the carpet by preheating the to-be-mated faces of the car2et and the sound-deadening sheet by appropriate means ~ovens, IR heat), and the final structure ass~mbled. Assembly would take place through applying pressure to the mating faces, as for example, by a set of nip rolls. This technology is similar to that taught by Ballard U.S.P. 3,940,5~5.
Effectively, all o the routes described above would apply with equal foroe to the preparation of carpet for flooring uses. The final product obtained would be different from standard floor-type carpet in that it would not require a sheet of secondary jute or synthe~ic scrim, for reasons given above and covered in the Ballard patent. It would be different rrom au~omotive carpet primarily because of face-side st~ling 1~

differences~
Thus, the initial processing steps would be tufting, dyeing, drying, as described above--followed by precoating, as described above--followed by applica~
tion of the heavy eoat (sound deadening coat) as ~escribed in Ro~ltes (1) - (3! above.
Surprisingly, it has been discovered khat when a superfine fille~ is used in compounding highly filled processing oil modified thermoplas~ic com~osi-lG tions, rather than the coaxser-ground fillers generally ~mployed for products of this type, the following benefits result.
1. Par~icles of t~e produc~ are smoother following extrusion of stran~s and cutting into pellet formO
2. The bulk densl~y is increased.
3. The smooth pellets hold very ~ittle water and thUs are easily dried. Compara~ively little energy input is needed to dry smooth pellets.
4. The pellets which have a smooth surface do not "bridge," and hence will flow much fas~er under equal handling stress than do pellets which have rough surfaces.
5. As a result of the above, manufacturing ~5 rates can be improved, energy inpu~ needed to dry off pellets is reduced, and need for added labor to unload rail cars is avoided or sharply lowered.

6. It is anticlpa~ed tha~ extrusions ln other than round stra~d form will also benefit sub-stantial~y ~rom a smooth sheet, free of melt fractureeffects.
NoO 9 l~hiting which has been used extensively in sound deadening compositions (about 95% through 325 mesh, maximum particle size of at least about 95~ by weight i.s about 44 microns and mean particle size by weight is about ~ 7~
20 microns) often represents a viable midpoint in coarse--ness, availability and cost. ~s men~ioned abo~e and shown below, it has bee~ found that a surprising difference can be attained by use of filler particles which are much finer than those found in #9 Whiting~ Specifically, when ultrafine (paint - use) powdered filler such a5 Atomite* or Microfill* #2 is substituted for ~9 Whiting, the ~inal strand (rod) or sheet-~orm product, upon extru sion in conventional equipment, will be smooth. Where ~9 Whiting is employed, melt fracture effects can be severe. By substituting "Atomite", "Microfill ~2" or an equivalently fine (paint type) filler for the coarser #9 Whiting (a caulk or putty grade, widely used also for plastics or elastomer extension), the final thermoplastic blend will exhibit little or no melt fracture even though no other changes are made in composition or in extrùsion conditions.
The particle size o~ the filler employed in the compositions of the present invention should be suficiently fine to enable production of a smooth continuously extruded sheet, strand or tube, substan-tially free of melt fracture and such that when the strand is pelletized, it yields pellets that are free flowing.
Generally, at least about 95% by weight of the particles of the filler should have an equivalent spheri~
cal diameter smaller than about 25 microns, and at least about 50% by weight of the particles of the filler should have an e~uivalent spheri.cal diameter smaller than about 1~ microns. Even better surface characteristics are obtained when the above 95% and 50% diameters are smaller than about 12 a~d about 6 microns, respectiYely.
Most preferred surface characteristi.cs are obtained when the above 9~ and 50% diameters are smaller than ab~ut 8 and about 3 microns.
Table XIII show5 detailed physical property dat~ for ~any commonly used commercial fillers. Th~
proper~ies tabulated are based upon literature of *denotes trade mark communica~ions fromthe manufacturers; but, as changes will occur due to vaxiations in raw material sources, equipment condition, and market conditions, those who work in this field are cau~ioned to contact manufacturers 5 to be cer~ain the products or possible interest reMain available and ~o obtain tne most recently available data concerning them,.or newer possibly preferable replac~ts.

7z~
2~
TABLE XIII
Typica l Phy ~
Particle Size Information FillerTrade Name % on No. ~ :~verage ~ 325 Mesh (Microns ) (Microns ) "P,tomi~e" ~T-W) 2 . 50 . 5 to 10 practi-cal ly O
2Gama~Sperse* 3 . 499. 5% ~12 O. 005D6 6532 ~(~.M. ) max.
3Snowflake* ~T-W) 5.01.0 to 20 practi-cally 0 4Duramite* ~T-W) 142O5 to 25 practi-cally 0 5Wingdale* (G.M.) 8O499.5% <42 0~2~ max.
6 "Micxofill" #2 ~CC)6.098~ <30 2.5~ max.

7 Drikali~e* (T W~ 5.5 1.0 to 44 traces

8 ~9 Whiting (G.M.) ca.20 -~ 9.0% max~

9 "LC" Filler ca. 25 to 25 -- 15-20~
(G~M,) typical Calwhite*~G.M.) 5.4 -- 0 n 008%
max.
11 #22 Barytes (T.W.)12.0Up to 60 0.5~ max.
(1) Data are bas~d on manufacturer's literature 25 ~2 ? All are ground limestone except for NoO 11, which ~ barytes. 5upplier code is:
CCC = Calcium Carbonate Company, Marble Falls, Texas.
GM - Georgia ~arble Company, Atlanta, Georgia.
T-W - Thompson~ Weinman & Company, Cartersville, Georgi~ .
(3) Relatively coarse fillers are generally specified by the mesh siz~ of progressively fi~er screens.
The finest scree~ size in general use is 325 mesh;
fine~ scree~ "blind" easily, are hard to clean wi~hou~ damage, and are llttle used. The rela~ion~
ship be~ween scxeen size and par~icle size is * denotes trade mark '7~

~iv~r. belGw.
U.S. StandaYd Particle Diameter(a) in Sieve NO.
100 149 0.149 0.0059 ~g 73~7 0~0737 0.0029 27~ 53/3 0.0533 0.~21 325 44.5 0.0455 0.00175 400 38.1 ~.0381 0.0015 (a) Diameter means equivalent spherical ~iameter, i.c., the diameter of a sphere having the same volume as that of the particle. It is measured by standaxd means which are defined by the Pulverized Limestone A~sociation.

In commercial practice, when ~9 ~hiting was used or instead a slightly coarser grade, "LC filler," was employed, we found the particles produced by a conventional melt cutter to be rough when making highly filled blends of ~he type described earlier. In turn, during com~ercial shipment, time, vibration, and pressure cause the pellets to compact and interlock, which requires added time and labor to transfer the product. Smoother pellets made from finer particle size filler do not bridge or interlock and t~us are substan-tially free of unloading problems. A further benefit found when pro-cessing pellets of t~.e present invention is the ease o~ drying the final product. Rough pellets from a melt cutting unit tend to hold subs ~ tial amoun~ of free water in crevices. ~en smooth, dense pelle~ are produced, there is essentially no way that water can be entrained. ~Ience, smooth pellets can be dried rapidly with little energy input ~ comparison to that needed when ~ry~g rough, very wet pellets.
Similarl~y, when a sheeting die is usedl the extrudate from blends high in filler often exhibi~ melt 20 ~racture. ~ severe enough, this can cause holes ~o ~orm in the sheet. Use of ultrafine fillers combats melt fracture, thus providing greater manufacturing latitud~ when extruding sound-deadening or other types o sheeting.
The followi.ng examples are qiven or the ~_rpose of ilLustrating the present i~vention. All parts and percentages are by weight ur.less otherwise speciied.
Comparative Examples 1~9 . . . _ _ These examples show the increasing dif~iculty encountered in making highly ~illed binary blends using EVA resins as the sole binder. All ingredients were premixed in a one-gallon (about 3.8L) can by shakin~
manually for about 0.5 minutes. The charge was then added to a Banbury-Type ~aboratory-sized intensive high shear mixer. Mix conditions used were fluxing for 3 mlnutes, at a temperature of about 325-375F (about 160-190C). Compositions and physical properties are summarized in Table XIII. When a high molecular-weight, 18~ vinyl acetate (VA) containing resin was used, increasing the filler (CaCO3) level to 65% from 55%
reduced elongation tenfold. A further filler increase to 72.5% resulted in a mixture which no longer would flux in a Banbury mixer. The "product" emerged as unblended, dry ingredients. In similar fashion, use of a lower molecular-weight, 18% VA containing resin or of a softer and also lower molecular-weight E~A resin blend did not enable fluxing in a Banbury mixer at 72.5% filler loading~ ~ddi.tion of filler caused one other pronounced efect-~the stiffness o the blend in^reased 7~4 ~6 TABLE IV
CO2IPOSITION A~D PHYSICAL PROPE~TI~S OF
EVA -CaCO3 BLEND~S

Ingredients Ex. Cl Ex. C2 Ex.C3 Ex.C4 Ex.C5 ~x.C6 EVA ~1~1) 45 35 27.5 - _ _ ~VA #~2) 27.5 EVA ~3(3) EVA ~4(4) ~9 Whiting (5~ 55 65 72.5 55 65 72.5 Physical Properties . . _ ~
Si~ o G~ Blend 1.47 1.59 1 1.39 1.55 Tensile Strength, PSI(S) 1050 904 WILL 662 706 WI LL
Tensile Strength, k Pa 7240 6230 NOT 4560 4870 NOT
Elongation, %~6) 455 ~2 34 23 Thickness o~ Strip, FLUX F~UX
Mils 74 70 68 68 MM 1.88 1.78 1 1.73 1.73 Sti~ness of ¦
Strip, g (7) 160 157 J 99 121 2~

TABLE IV (cont.) COr~POSITION AMD PHYSICAL P~OPE~TIES O~
EVA -CaCO3 B~E~DS
Ingredients Ex. C7 E~. C8 Ex. C9 E~A ~
EVA ~(2) EVA ~3(3) 22.5 17.5 13.75 EVA ~4(4) 22.~ 17.5 . 13~75 ,~9 Whiting(5) 55 (,5 72.5 Physical Propexties SP. GR. of Blelld1.50 1.60 Tensile Strength PSI`~) 669 627 ~IILL
Tensile Strength, k Pa 4610 4320 NOT
Elonga~ion, ~ 25 401 Thickness of Strip, FLUX
Mils 68 68 MM 1.73 1.73 Stiffness of Strip, g(7) 94 114 footnotes:
(1)18% vinyl acetate, 82% ethylene copolymer; ~.I. =2.5 (2)18% ~inyl aceta~e, 82% ethylene copolymer, M.I. =150 (3)25% vinyl acetate, 75~ ethylene copolvmer; M.I. -2.0 ( )25% vin~l acetate, 75% ethylene copol~mer; MoI~
(5)Calcium carbonate, as co~mercial ground limestone;
Georgia ~arble Co.
(6)Te~sile st-ength and elongation measurements made on Instron~Tester using ASTM Method D1708 at crosshead speed of 2 in (5.1 cm)/min. Samples are 0.876 ir..
~2.23 cm) X 0.187 in. (0.47 em) in si2e~ at strip ~hick~ess sho~n in table.

*denotes trade mark 27 ......... ............................. .......................... ~ ........... .. . .

;7~

( )Stiffness of strip measured by placing a 1 in x 6 in (2.54 cm x 15.2 cm) strip on a platform scale, and measuring the force required to make the ends of the test strip meet, at room temperature~
(8)referred to water.
Examples 1-7 and Comparative ~
The blends o~ these Examples were prepared and their physical properties were determined in ~he same manner as those of Comparat~ve Examples 1-9~

10 Compositions and physical properties are summarized in Table V. C-10 has a relatively low weight ra~io--1.8--of filler to organic binder. When the ra~io is raised to 2.6~1, as in C-ll, the blend will not flux~ as noted earlier. Howeverf as shown in Example 1, at the 15 identical filler loading~ after having replaced part of the expensive resin with an inexpensive processing oil, a truly surprising result was obtalned- the mixture fluxed well in the Banbury mixer. E~en more surprisingly the blend of Example 2, which represents a further 20 increase in filler/resin ratio, (4.1/1) not only fluxed t~ell, but had properties of definite practical interest.
~or example, for comparison of proper~ies o two sound-deadening sheets, it is important to compare ~hem on an equal ~eight basis. That is, the two sheet density 25 values, in lb/~t2, (oz/yd2 or g/m2) should be equal or as close as is reasonably possible. Thus, sheeting or Example 2 was deliberately made thinner than that for C-10, to attain equal sheet density (70 mils x 1.59 = 61 mils vs the ex~erimentally-measured 58 mils, or within O.OQ3 in~ of goal thickness). Note that the stiffness of E~ample 2 sheeting is only about 1/3 of the s~ifness of sheet from blend C-10, and still has tensile and elorlgation properties which remain 35 in a commercially useable range.

'7~>~

A second comparison was made to learn whether this surprising finding was limited to high molecular-weiyht polymers such as that used in Examples 1 and 2.
Examples 3 and a, when compared to blends C-12 and C-13, sho~ the same effects even though the EVA g,ades used are equivalent to a much softer copolymer (higher VA
content) which also has a lower molecular weight.
Examples 5, 6, and 7 show blends with various combinations of filler, resin and oil and different ratios 10 of filler to resin. The resulting ~roperti changes i'LUs-trate t'.~e latitude available to the for~llator in seeking a desired balance of properties.

~5 TABI,E V
_ COMPOSITION AND PHYSICAL PROPERTIES OF
EVA -CaCO~- PROCESSING OIL BLENDS
f In~redientsEx.C10 E~. ~1 E~ . 2 E~. C~ EX.C13 E~. XI 35 2?.5 20.5 17.5 EVA #3 ~ 17.5 13.75 EVA ~4 ~ 17.5 13.75 #9 Whiting65 72.5 72.5 72.5 65 72.5 "CIRCOSO~' 4240(1) ~ 7 10 - -Filler/Organic Ra~io 1.8/1 2.6/1 2.6/1 2.6/1 1.8/1 2.6/1 Filler/Re~in Ratio 1.8/1 2.6/1 3.5~1 4.1/1 1.8/1 2.6/1 Physical Propertles SP. GR. of Blen~1 1.59 '1.821.81 1.60 20 Tensile Strength, PSI 904WILL649 636 627 WILL
Tensile Strengt~ k Pa 6230 447Q 4390 4320 Elongationr ~ 42NOT 21 23 401 25 Thickness ~LUX ~LUX
of Strip, ~ils70 59 58 ~8 MM1.78 1.50 1.47 1.72 Stiffness of Strip, g 157 89 57 114 7~
, TABLE V (cont.
... . ..
COl~lPOSITION AND PHYSICAL PROPERTIES OF
EVA -CaC03- PROCESSING OIL BLENDS

, ~
!lgred i .~ ~s ~ . 3 _x . ~s Ex. 5 E,~. 6 Ex ~ ~ 7 Z~
EVA " 3 9 . 7 ~ 8 r 7 5 9 ~ 2 5 1 0 ~ rj EVA ~4 9.75 8.759.011.25 10.5 ~9 Whiting 72 . 5 72 . 575 .070.0 70.0 10 "CIRCOSOL" 4240tl) 8 10 7.0 7O5 8.0 Filler/Organic Ratio 2~6/1 2.6/13/12.33/1 2.33/1 Filler~Resin Ratio 3.7/1 4.1/1 4.2/1 3.1/1 3.33/1 Physical Properties ,, ~
SP. GR. of Blend 1.8L 1.821.871.76 1.76 Tensile Strength, Tensile Strength, k Pa 3280 283040303840 3360 Elongatlon, ~ 27 3319 37 38 Thickness o Strip, ~ils 59 S~59 62 62 MM 1.50 1.501.501.57 1.57 Stiffness Of Strip, g 53 4573 65 62 (1) A naphthenic processing oil available from Sun Petroleum Products Company. The CQmposition for the oil as given by the supplier is 39~ naphthenic carbon~ 40~ paraffinic carbon, and 21~ aromatic carbon. Viscosity at 100~. is 2525 SUS. Specific 35 gravity is 0.9490.

7 ~ '~

Examples 8-11 ~hiting (CaCO3) is a very common and cheap filler with a density of about 2.7 gJcm3 One might elect to employ a very dense, but more costly, filler to achieve a special purpose. Table VI illuskrates some ways the new technology can be employed with a dense filler. Blend pr~paration and determination OL
physical properties followed the procedure outlined in preceding examples~ Example 8 shows a blend which contains 75~ whiting by weight--or a~out 51% hy volume.
Examples 9 and 10 show the results when barytes is used instead, on a ~imple substitution basis, by weiqht.
Example 11 shows properties a-tainable, when barytes is substituted for whiting, by volume~
These changes are very significant in specialized uses, e.g., sound-deadening sheeting or backing. For example, the compounder has several choices:
(a) For maximum weight a~ equal coating thickness, ~xample 11 would clearly prove superior.
(b) For equal weight at minimum coating thicX-ness, ~xample 11 woulcl again prove superior.
(c) Conversely, where maximum coating thick-ness is desired, at a given weight per unit area, Example 8 would ~rove best.
The data summarized in Tab'e VI were delibera tely generated in a way to produce nearly equal weights per unit area. If instead the test plaques had been m~de at equal thickness, the values noted or relative stiffness would change markedly. This represents another option available to one skilled in the art to practice the present invention, whereby a radical shift in goal pro~erties can be securod. In using the above data, it is importa~t torealize thatsmall shi~ts in thickness or in methods of sample preparation can cause variations in measured values without departure from the essellce o~
the invention.

TABI.E VI

EVA - CaCO3 or BaSO4 - OIL BLENDS
IngredientsEx~ 3 Ex. 9 Ex. 10 Ex. 11 ..... . . . _ ,, _ ___ EVA #3 10 10 8.75 6.1 EVA ~4 10 10 8.75 6.1 ~ Whiting 75 _ _ _ Barytes(l) - 75 75 82.5 "CIRCOSOL" 4240 5 5 7.5 5.3 Filler, ~
by Volume 51.3 39.5 39O5 50.7 Physical _o~erties SP. GR.
of ~lend 1.87 2.32 2.28 2.67 Tensile Streng~h, PSX685 555 345 229 Tensile Strength, k Pa 4720 3830 2380 1580 Elongation, ~18 700 561 68 Thickness o Strip, Mils 58 47 48 40 ~ 1.47 1.19 1.22 1.02 Stifness of Strip, g 84 34 25 24 (l)A heavy filler having a de~sit~, of about 4.4 a/cm3 consisting primarily of BaSO~, obtained from commercial source5. For Example 9, ~22 Barytes from Thompson, Weinman was used. For Examples 10 and 11, Dresser Industries ~85 Barytes ~as used. For all practical purposes, the mate.rials are considered to be in~erchangeable.

2~

Examples 12~13 and Com~arative Example 14 Following the procedure of preceding examples blends were made with E/EA copolymer in place of the EV~ copolymer. The results obtained ~Table VII) were similar to the ones obtained with EVA copolymer.
The addition of"Circosoll' 4240 to a binary blend enables use of a much-increased filler loading, while maintaining a praciical degree of tensile strength and elonga~ion characteristics and while appreciably reducing ~he stiffness of the final compound.

~0 TABLE VII
COr~lP~SITION AND PHYSICAL PROPE~TIES OF
E/EA -CaCO~- ~IL BLENDS
Ingredlen~s Ex. C-14Ex. 12 E~. 13 ~ _ _ .... .
5 E/EA(l) 45 20.2 17 ~9 Whiting 55 72~5 75 "CIRCOSOL" 4240 - 7.3 8 Physical Pxo~erties Sp.~R~ofBlend 1.46 1.76 1.83 'l'ensile Strength, PSX 715 55~ 500 Tensile Strength, k Pa 4930 382G 3450 Elongation, % 73 15 15 ThicknesS
of Strip, ~ils 75 61 59 MM 1.90 1.55 1.50 Sti~fness o~ St~lp, g 1~1 94 95 (l)Ethylene/ethyl acrylate copolymer, grade DPDA 6182 NT, obtained from Union Carbide Corporation, contains about 16~ ethyl acrvlate, about 84~ ethylene, and has a melt index of about 1.5.

7~

Examples 14-l9 These examples illustrate the use of different interpolymers in practicing the p~esen~ inventionO Pre-paration and evaluation of the blends follo~d the S procedure of preceding examples.
Compositions and physical properties are summarized in Table VI~I.
~ rhe blends of these examples are free of surface tack and exuded oil at ambient tem~erature.
One skilled in the art can readil~ make a wid~ assortnent of changes, such as.
(a) Using blends of interpolymers.
~b) Using alternate fillers.
(c) U~ing other oil ingredients, such as aromatic or paraffinic oils, in plac~ of all or part of the naphthenic oil used in Table VIIIexamples. It is, o~ course, possible to use oils of higher or lower viscosity to secure special effects.
(d) Adding other ingredients, such as waxes, rubbers, elastomers, tackifiers, plasticizers, ex~enders, resins, etc. such as are widel~ used in compounding of hot melts and extrudable compositions.

3~

37 ..~.~ 5 7~ A ~
TABLE VII r COMPOSITIOM AND PHYSICAL PROPERTIES OF
BLENDS OF ETHYLENE-INTEXPOLYMERS, CaCO3 AND OIL
5In~redientsEx.14Ex.15 Ex.16Ex.17 Ex.18 Ex.19 E/IBA #l~lJ20.2 E/IBA #2(~ ~ 20.2 E/~$~A ~1(3) - ~ 20,2 - - ~
E/MMA #2(4~ - - _ 20.2 E~A #3 - - ~ ~ 10.1 Terpolymer ~1~5~ 10.1 Terpolymer #2(6) _ _ _ ~ _ 21 #9 Whiting72~572.5 72.5 72.5 72.5 70.0 "CIRCOSOL"4240 7.3 7~3 7.3 7.3 7 n 3 9 ~ O
SP~GR. of Blend 1.84 1.81 1.81 1.84 1.85 1.74 Tensile Stxeng~h, P5I 227 536 579 349 381 546 Tensile Strength, k Pa1570 3700 3990 2410 ~63~ 3760 Elongation, ~ 50 23 22 46 34 63 Thicknes~
of Strip, Mil~ 5~ 5~ 59 58 58 62 MM 1.~7 1.50 1.50 1.47 1.q7 1.57 Skifness of Strip, g24 73 71 37 52 56 (1) ethyl~lle/i~obutyl acrylate copolymer, 32~ isobutyl acrylate, 68% ethylene, 1~7 MI.
(~) ethylene/isobutyl acrylat~ copolymer, 20% isobutyl-acrylate 80~ ethylene, 2.5 ~I.
(3) ethylene/methyl methacxylate copolymer, 18% methyl methacrylate, 82% ethylene, 2.2 MI.
(4~ ethylene/methyl methacrylate copolymer, 31~ methyl methacrylate, 69% e~hylene, 7.2 ~I.

Table VIIIfootnotes (cont.~
(5)ethylene/carbon monoxide/vinyl acetate terpolymer, 65.5% ethylene, ll~ CO, 23.5% vinyl acetate, 35 MI.
5 (6)ethylene/vinyl acetate/methacrylic acid terpolymer, 74~ ethylene, 25% vinyl acetate, 1~ methacrylic acid, 6 MI.

Examples 20-23 ,~ These examples illustrate how the melt index of the blends of the present invention can be controlled over wide ran~es by the amount of oil ernployed. Com-positlons and results are summarized in Table IX. ~elt index is of substantial prac~ical importance to those who extrude cornpounds into sheet form or mold it into appropriate shapesO By proper control of melt index, optimum extrudate properties can be secured, or properties can be matched to ~he capability o F available equipment.

.

: ' _~ 1. IJ' EFFECT O~ INCREASING OIL CONTENT ON THE
_ MFLT INDEX OF THE BLEND
~ ents_ ~x 20 Ex. 21 Ex. 22Ex. 23 S Base Compound~l) 100 98 96 94 "CIRCOSOL" 4240 - 2 4 6 Melt Index O~
Blend(2) 1.79 3.39 4.90 9.65 (1) Consis~s of (a) 20% of EVA copolymer having 25~ VA, 75% ethylene, & 2MI; (b) 4~O of EVA copolymer having 7.5% VA, 92.5% ethylene, ~ 1.2MI; (c) 6% of "CIRCOSOL" 4240 and (d) 70% o~ ~9 Whiting.
(2)Determined by ASTM Method D 1238 , at 190C

572~

Exam~le 24 and Comparative Exam~le C-15 The blends of this ~xample were compounded in a laboratory-scale Banbur~ mixer for convenience, as previously described, and were then processed into sheet form in a conventional two-roll mill. To make test plaques or sheets, the desired amount of blend would be weighed, placed in a laboratory-scale heated press, and pressed (between smooth release sheets of Teflon~ fluoro-carbsn resin) in a die of appropriate thickness. For convenience, the present die had an openlng of 6" x 6", was cut from sheet: stock of 58 or 65 mils of thickness, depending on blend density, and was charged in most instances with ~3 gxams of resin blend. This corresponds to 5 lbs./yd.2, a commonly used sheet weight for automotive carpet use. A typical cycle was:
(1) Place a Teflon~ sheet on lower press platen or on top of a smooth steel ~aseplate if the pLaten ls not truly smooth.
(~) Place an 8" X 10" die plate (6" X 6" opening~
atop the Teflon~ sheet.
(3) Put 63 g. of resin in the cavity. (1-2 gxams surplus may be needed as some blend may ooze out during pressing).
(4) Place a Teflon~ fluorocarbo~ sheet atop the resin. Add a smooth steel upper plate if the platen is not truly smooth.
(5) Heat the press to 175C.
(6) When the press reaches 175C., slowly pump the press closed to a total pressure of about 12,500 pounds (150 psi, approximately).
(7) After 2 minutes, raise the ram pressure to 50,000 pounds (600 psi, approximately)~ and hold the pressure and temperature constant for about 1 minute.
(8~ Shut off heat and cool press to ambient temperature with ram in closed position.
(9) Release pressure, remove sample, and cut to appropriate shape for further testing.
~1 - - - - - ~ - - - -(10) Age samples overnight at 50~ RH and 72F.
In evaluating highly filled blends, great caxe and good technique must be used in making all samples, as surLace imperfections will cause wide variations in measurements of tensile strength and elongation.
The composition of this Example, i.s ~iewed as preferxed and as a logical starting point for a compounder because it offers an excellent balance of proper-ties (cf. Table X). For example, the tensile stren~th value at 550 psi ~3790 kPa~ is high enough for an~i.cipated uses for filled thermoplastic blends. Further, ~he elongation noted, at 455%, is outstanding ~or a highly filled hlend. Despi~e these excellent properties, the stif~ness value for the compound is only 76 g. vs.
the high 118 g. for the oil-free comparative blend, C-15. As this balance of properties indicates,.the blend o~ Example 24 can be readily prepared from its ingredients and also can be readily extruded into sheet form. On the other hand, Blend C-15, compared to Blends C-12 and C-13 (Table V), has about reached the ultimate upper limit fox filler load on an oil-free basis. The com-pound tensile strength has jumped sharply,andelongation has dropped sharply vs. Blend C-12. Physical propexty data for Blend C-15 were no~ easily determined, as it was ~ery difficult to make good, reproducible ~est coupons using so high a filler loading without inclusion of oil.
The above preferred blend does have a drawback;
it is possible to produce more highly filled compositions, with an e~ual or hi~her oil content, nd thus save sub- ~
stantially in raw material costs at the expense of ph~sical properties. For example, compare the physical properties of the blend of Example 24 with the properties o~ blends o~ Examples 3 through 7 in Table V. The latter blends, while still useful for man~ purposes, have about l/3 less tensile stren~th and about l/10 the elongation--surely a major reduction. However, because EVA copolymers cost over 50¢/pound vs. less than 10~/
pound for oil and about a penny per pound for filler, it i5 readily ap~arent that many users will want to pursùe the highest possible filler level aggressively.
This is particularly true for automotive and other sound-deadening sheet, which depends upon mass for i~s effective-ness and often does not require great blend strength.
Thus,itiS likel~hatmany industrial users will take the above l'preferred blendl1 and reduce its excellent tech-nical properties ~o a lesser level which will still be technically adequa~e for their uses and will be much more attractive from a competitive economic viewpoint.
A skilled compounder will realize the trade-offs and options open to him in reducing performance to reduce ~xice and can vary substantially the blends provided in the illustrative examples without departing ~rom the spirit of ~he invention. Compounders can also elect to vary blend properties by substituting other grades of EVA copolymer for all or part of the EVA #3 content.
For example, use of an EVA copolymer having a lower VA
content or a lower MI or both, as shown in the blends of Examples 20-23, (Table IX), will provide a stiffer blend with improved resistance to deformation at tem-peratures above ambient. Similar changes can of coursebe effected by adding small amounts of unrelated resins, rubbers, elastomers, extenders, etc. without departing from the spirit of the invention.

5~

TABLE X
PREFERRED SOU`~D-DEADE~IN~, COMPOSITION
_,. _,. . . . . .
Inqredients E~ample 24 Example C 15 EVA X3, % 26.5 33 "Circosol" 4240, % 6.5 --~9 r7~iting , ~ 67.0 67 Ph~sical Propexties:
Sp. Gr. OL Blend 1.72 1.72 Tensi le Strength - psi550 895 - kPa3790 6170 Elonga~i~n,% 455 gg Thickness of Strip, mils 65 S5 Thickness of St~ip, ~m1.65 1.65 Stiffness of Strip, g 76 118 Exam~les 25-26 and Comparative Example 16 These examples show that even readily fluxable EVA/filler blends having a rela~ively low filler content ean be usefully altered bY addition of small amounts of S a processing oil. Compositions and results are su~marized in Table XI. Blend ~-16, for example, is a ve.ry stiff compound with good elongation and with a high tensile strength. To make the blends of Example 25 and Example 26, the resin content was reduced by 5% and 10~, respectively, and replaced by processing oil. The elongation values and the densitv were ~irtually unchanged.
However, the blend became su.r~risingly softer, yet retained a good tensile strength value. Thus, addition of oil to a ~illed EVA system conerred benefits.

'7~

TABLE XI
COl-iPOSITION AND PHYSICA!J PR~PF:RTIES
EVA -CaC03 -OIL BLl~r)s ~T ~ 5 % FILLER I.OAD
.. _ _ , .. . . . . . .
Ingredlents ~'x. _-16Ea~. 25 Ex- 2.6v~
EVA ~1 45 40 35 ~9 Whiting 55 5S 55 "CIRCOSOL" 4240 - 5 10 Ph~ical Prope_ties SP. GR. of 13lend 1.46 1.48 1.47 Tensile Strength, P5I 935 618 491 Tensile Stxeng~h, kPa6450 4260 3380 Elongation, ~6 3 9 6 3 4 83 8 4 Thickness of Strip, Mils 74 74 74 ITm 1.~8 1~8 1.8~
Stiffness of Strip, g 153 99 72 ~ `

~ F ~
The composition and physical properties of the blends of ~hese exam~les are summarized on Table XII~ The blends were made with a ~ixed pxoportion of ~VA resins plus fillers ~ollowing the procedure of preceding examples. ~hile the percentage of oil present has been held constant, the type and viscositie5 have been varied.
Of the 9 oils tested in this series the aromatis oils showed no tendency to exude, while the paraffinic oils exuded. Of the naphthenic blends, only the Example 28 sample showed an exudation tendency. This sample contained "Fle~on" 766, which has 54~ paraffinic content, 45~ naphthenic, and 1%
aromatic. By contrast, the other three naphthenic oils had a paraffinic oil con~ent of 42~ or less. Thus, the need to carefully examine the type o~ oil s~lected is evident to ensure attaining the desired surface charac-teristics (i.e., dry or oily) for the final produc~.
A11 of the blends had about the same specific gravity, and thus the same thickness strips were com-paxed. Results show the highest stifEness resulted when the highes~ molecular-weight oil was used. Further, scouting tests (not tabulated) showed that the blends made with low molecular-weight (low viscosity) oils had better resistance to flexing at temperatures below zero degrees Fahrenheit.

~0 7;~

TABLE XI I
COMPOSXTIOM AND PHYSICAL PROPERTIES
OF EVA CaC03-OIL BLENDS CONTAINING
DIFFERENT TY~ES OF OIL
.
Ingredients: EVA ~3 & ~4 = 8% of each OIL = 9%
FILLER (CaC03 ) =75%
(1) Ex. 27 Ex. 28 Ex. 29 Exo 30 Exo 31 T~7p~ ~7f Oil C450 (N)F7~6 (~)C4240(N)C5600 (N) F340 (A) Physical Proper~ies:
.. . .
SP . GR . o f Blend 1. 87 1. 86 1. 88 1. 87 1. 87 15 Tensiïe Strength, PSI 431 422 397 477 385 kPa2~72 2910 2737 3289 26i4 Elongation, % 15 22 19 21 21 Thickness 20 oE Strip,Mils 58 59 59 58 58 ~run 1.47 1.50 1. 50 1.47 1.47 Stiffness of Strip, g 47 45 40 55 46 Exudatiorl .
25 Rating NONE HEAVY NO~E NONE NONE

O

2~

4g TABLE XII
COl~lPO::)ITION AND PHYSICAL PROPERTIES
OF EV~-CaCO3-OIL BLEWDS CONTAINING
DI~FE~ENT T~?E.S OF OII, Ingredients: Æ-\IA ~. 3 & s4 ~ 8% of each _ OIL = 9%
E~ILLER ~CaC03 ) =75~
Ex. 32 Ex. 33 Ex. 34 Ex. 35 T~rP~ Of C3il(l) 579n (~)S~500T(A) T60(P) T80 (P) - Physical Proper~ie s:
SP.GR. of Blend 1.88 1.88 1.87 1.85 Tensile Strength, PSI 560 505 463 401 kPa 3861 3482 3192 2765 Elongation, % 18 22 24 18 Thic}cness o~ Strip, ~ils 58 58 58 58 lrun 1.47 1.47 1.47 1~47 Stif fness of Strip, g 63 60 47 50 Exudation Rating NONE NONE HEA~ HEAVY

(1) K~y is:
C = "CIP.COSOL"
3 o F = "FLEXON"
S = " S U~IDEX "
T - " TUFFLO "
(N) = NAPHTEIENIC
~) = ARO~IATIC
3 5 (P) = PAR~FFINIC

7~
, Examples 36-44 and Comparati~e_Examples 17-18 These examples are summarized in Table XIV
Comparative ExaMples 17-18 sh~w the characteristics of pellets o~tained when highly filled blends are made using relatively coarse fillers.
Sample Preparation:
All ingredients were premixed in a one-gallon (about 3.8 1) can by shaking manually for about 0.5 minute. The charge was then added to a Banbury type la~oratory-sized intensive high-shear mixer. Mix con-ditions used were fluxing for 3 minutes at a temperature of about 325-375F~ (about 160-190CC.). ~nless indicated specifically to the contrary, all blends made contained 7205% of the filler to be evaluated, plus 20.2% of a blend of EVA resins and 7.3% of a process oil, as identified in Table XIV.
The hot, fully fluxed blend from the Banbury mixer was then passed through a standard-type two-roll mill to ~r~ a thin sheet (thickness = about 2 to 3mm).
~ Ater cooli~g, the sheets in turn were reduced to small chips which could readily be fed to a conventional extruder. Our tests were made using a co-rotating twin-screw Werner~Pfleiderer* extruder fxom which the product emerged as two about 3/16" diameter strands. These were water-cooled, and then chopped by means of a Cumberland Cutter into pellet form (right cylinders of about 1/8 X
1/8 inch`. Before the pellets were chopped, the strands fed into the cutter were blown with a stream of low-pressure air to blow off as much water as possible.
The pr~duct pellets were evaluated at once ror relative degree of water content, prior to tray-drying the pellets under ambient conditions.
After dxying of the pellets, their principal physical properties were evaluated:
3S Visual Rating of Extrudate ~Strand Smoothness~;
This was rated visually and by touch on uncut strands.
A ra~ing of 1 means the strands are smooth, round, and *denot~s trade mark essentially free of surface flaws. The sur~ace is so smooth that water droplets are readily removable by simple means such as an air stream. A rating of 5 indicates the strands are extremely rough, jagged, and cannot be dried by a simple, quick air-blowing step.
The rating system used is described in detail in Table ~V .
Pellet Water Level: On emerging from the Cumberl~nd Cutter*, pellets cut from fine-filler-contain-ing smooth strands are dry to the touch. By contrast, *denotes trad2 mark 7~

TABLE Vrv EFFECTS OF FILLER TYPE ON THE
PROPERTIES OF EVA-BASED BLENDS( ) AT 72.5% FILLER LOADING
__ S Bulk Average Vi~(4) Den- Vi~() Ex. Fill~r(2)Yæticle E~ate RX~ Rate(5) _sity(6) Water No~ No.size(3) Ratin~ 68-74F 90-95F g/ml. Level (Microns) 36 1 2.5 112Q,000 60,000 1.02 Dry 37 2 3.4 1~120,000 13,300 0.98 Dry 38 3 5~0 1~80,0001263 0.95 -- (g) 39 4 14.0 3~2 1180 29 0.92 Mod.Wet 8.4 3706032 0.94 ~- (9) 41 6 6.0 240,000286 0.97 Dry 42 7 5.5 1~2 48,000 1560 0.97 Damp C~17 8ca. 20 3~2 122 -- (8) 0.89 Mod.Wet C-18 9ca. 26 53 -- (8) 0.82 Wet 43 10 5~4 1~4800 2400 0.93 Damp-Dry ~4 11 12.0 1~1~0,000 10,000 1.~2 -- (g) (l)All blends i.n this table contain:
~a) EVA ~1 = 16.2~; 25~ VAc; 75~ ethylene; 2 ~II
(b) EV~ ~2 - 4~; 7.5% VAc; 92.5~ ethylene; 1.2 MT
(c) "Circosol" 4240 - 7.3~ naphthenic proces-sing oil available from Sun Petrole~n Product~
Company. The composition for the oil as given by the supplier is 39~ naph~henlc carbon, 40~ paraffinic carbon, and 21~ aromatic carbon.
Viscosity at 100~ is 2525 SUS. Speclfic gravity i~ 0.9490.
(d~ Filler = 7205~
t )Fillers are described in Table XIII-( )Typical values rom suppliers' charts or graphs.
These are not speci~ications and thus may v-ary moderately from values given.

TAB~E ~XIV ~continued) 1 )For details of rating system, see Table ~V. Rating of 1 is very smooth and "best"; 5 is vexy rough and "worst."
( )Pour Rate is given ~ grams per 10 min. High values are best. See "Descrlp~ion o~ Pour ~ate Test" balow.
(~Bulk density was measuxed by filling a 500-ml gradua~ed cylinder tG the 500-ml mark. Filling was accomplished by slow, careful pouring of ~he pellets in~o th cylinder, without vibration or tamping.
Weight of pellets was measured in grams. Data were calculated in gr~ms/ml.
(7)Visual wa~er level: As described in more detail under "5ample Pxeparation," cooled s~rands ex the water bath are blown with an air s~ream to remove water ~ fore the strands are chopped. The pellets from the Cumberland strand cu~ter are examined care-fully or the presence of water~ The ratings as used in Table XIV are:
Dry: The pellets are dry to the touch and will not deposit water on a paper towe1.
Damp: Pellets are not ~uite dry to the ~ouch and deposit only traces of water on a paper towel.
Moderately Wet: Pellets feel wet and a few water droplets will transfer readily to the hands or to a paper towel.
Wet: Pellets contain much free water, some of which can be seen with the naked eye. Water transfers in drople~ form ~rom a handful onto the ha~ds or forms wet patches on a pape~ towel.
(8~Not tested; samples would surely block.
(9)~o observations made.

~4 when a coarse f iller is used ~ the pellets carry much free water, which we~s the hands, blotting paper, etc.
(see also Tal:le XIVJ footno~e 7) .

TABLE X~.
RATING OF EXTP~UDATE STRAND PROPERTI}~S
1 = sest - No roughness discernible to naked eye or to ~he touch on close examination.
2 - ~ ~ Slight roughness discernible to naked e~e on close examination. Strands feel smooth to touch~-but .not so smooth as for a ~1 xating.
3 = Fair ~ Casual visual examination from close distant-e shows slight pock holes or ridges on extruded strands. A casual observer would readily classify strands as being rough to the touch.
4 = Poox = Strand xoughness is readily apparent to all observers at arms ' leng~h.
Strands are def initely rough to the touch .
5 3 Ver~h - Stxand roughness is severe and is _.
easily detectable at a distance of 5 ~o 10 feet from the sample. l?rom a close distance, the sample has siæable ridges,and pock marks. The strand looks and feels much like a very coarse rat-tail file.

3~

~ 2~
Bulk Density: Rough strands cut into pellets ob~iously produce rough pelle~s which require substan-tial space in a container. Thus~ the bulk density value for smooth pellets mad~ from fine fillér is substantially higher t~.an that measured when the same procedure is used with rough pellet~. For a valid comparison, it is e~ential that the pellets being compared have the same specific gravltyO I~ is ~or this reason that most of oux data are presented at a unifoxm 72.5~ filler loading.
Pour Rating: When a bulk flow or pour rating test is conducted on pellets made containing fine particle size filler~ the smooth pellets flow instantly from the ~est vessel. ~y contras~, as the pelle~ rough-ness is increased, the pour rate falls sharply, ~ventu-lS ally reaching a "no-flow" condition for "Control"
pellets made usin~ the coarse-grade "LC" filler. For kest details, see "Description of Pour Rate Test," given below.
Descrip~ion of Pour Rate Test:
A key property of substantial importance for a bulk-shipped pelletized product is ~he ability of the blend to be emptied ~uickly and completely from a rail car. During rail car shipment, a series of events occur--all o which magnify the tendency of the contents o the rail car to "bridge" (interlock) sa that it may become difficult to unload quickly, without special labor-intensive pxocedures:
JTime alone favors tendency to "bridge"--particularly by de~orming and interlacing of rough.
pellets.
-Pressureenhances tendency to defor~ and interlock.
-High loading temperatures will sof~en thermoplastic pell~ts, khus increasing the tendency of the lading to def2rm and to bridge.
-Vibrationduring shipmen~ will acc2lera~
the tend~ncy of the lading to oompact, interlock, and "bxidg~." 56 5~7 As a full rail car is an impractical means to test the relative ease of handling, unloadin~, or storing of pellets which are subject to "bridging,"
a small-scale, quick ~est is required. A test which will do this has been devised. In brief, it consists of placing a known weight of pellets to be tested into a standardi2ed container at a predetermined temperature, applying substantial pressure for a short ~ime period, releasing the. pressure, and determining the rate of discharge of the pellets when the can is inverted.
Temperature of pellets can of course be adjusted to match precisely the conditions under which a rail car will be loaded~ By applying very high pressure for a short time, th~ compacting tendency of a long, slow rail car shipmen~ can be simulated.
The s~eps in carrying out the laboratory~scale block resistance test are:
1. Weigh 200 ~ 1 gram of pellets into a stand~rd 1/2 pint paintcan. (Inside diameter - 2.8 in.;
height - 2.9 in.) The pellet temperature should be regulated in advance to a desired value hy means of storage or an adequate time period in a laboratory oven. One hour preheating on a tray should suffice.
2~ Quickly place 2 kg standard~type laborator~ weight (diameter = 2.6 in.) atop the pellet charge. This ac~s as a pressure distributor and transmitter-- any other similar incompressible object with a diameter sligh~ly smaller than the paint can might be used ins~ead.
3. Place the can and the pressure transmittin weight in~o a standard-type laboratory press.
4 ~ Apply 4, OOQ pounds o force for 15 minutes (This is approximately 650 psi, far higher than will be encoun~ered under routine storage conditions.) .~s ~he blends are compressible, adjust the applied load to 4,000 psi at 3-minu~e intervals.

$~ 7~

5. Release the pressure; remove the can;
remove the weigh~, and gentl~ but rapidly lnvert the ca~ onto a wide-mesh (1~2 X 1/2 inch or larger) screen.
6. Using a stopwatch, measure the time requlred to empty the container~-or, alternately, fo~
blends with a poox flow rate, measure the amoun~ of pellets which fall from the con~ainer in exactly 10 minutes.
7. For quick and easy comparison purposes, cal~ulate the flow rate in grams/6.2 sq. in./min.
8. If desired, then convert the ~low rate to any desired system of units to simulate ~he exit opening from a ~ommercial storage system.
In practice, it may be desirable, depending upon the type, size, and na~ure of the pelletized compound, to use a higher or lower pressure, consist-ently, ~o a~tain comparative results. FGr example, where the pelle~s are soft and are severely ~istorted or compacted by use of a 4,000-pound pressure loading, it may be desirable to sharply reduce the pressuxe applied. Similarly, di~ferently sized containers may also be desirable where a closer-to~full-scale trial is o~ interest.
During our tests, the use o 4,000-pound pressure proved a good compromise in that very smooth pellets would not block and would pour from the container in less than one second. (Here, ~or conven-ience, we used a value of one second for calculating purposes.) Very rough blends would not flow at all--or might dischaxge 5 to 20 grams at the s~art of the maxi~um 10-minute test perlod allowed, and then s~op flowi~.
Note that the pellets shcwn in Compaxatlve ExampleQ C-17 and C-18 of Table ~IV are OL relatively low quali~y by all of the ratings described above. Visually, the strands were rated at 3.5 and 5, `7~
. 59 respectively-~ or poor to very rough on the scale shown in Table XV. The pour xate values are ver~ low--and correspond on an industriaL scale to sampies which r~ill barely flow from a rail car at am~ient conditions and may not flow at all at temperatures of 95~F. or over.
The fre~hly cu~, rough, undried pellets hold large amounts o water, which, under commercial conditions, will require large equipment and high energy input to at~ain significant tonnase out-put of a dry product.
A wet product i5 highly undesirable because: (1) Wet pellets will reeze into a monolith during wintertime rail shipment. (2) ~et pelle~s are notorious causes of problems upon extrusion or injection molding, and can cause personal injury or equipmen~ damage, plus a poor-quality product. Finally, because pellets are rou~h, they do not "pack" well-which will require a relatively large~volume shipping container to package a fixed weight of goods.
Examples 36,37, 38, 41, 42, a~d 43 ~how the dramatic and unexpec~ed improvements at~ainable when the rela-ti.vely coarse fillers used in Table XIV Comparative Examples C-].7 ox C~ re rep aced with fine fillexs.
By reducing the average particle size from 20-26 microns to about 2-6 microns, ~he following proper~ies improve:
-The extrudate roughness rating i5 in the range o 2 or better.
-Freshly cut pellets are dry or nearly so.
-Bulk density values have risen by a significant a~ount.
-Most important, pou_ rates have risen to rates which are far higher than those seen for blends C-17 and C-18.
As might be expected, when filler particles of an intermedlate size are selected, blend properties tend ~o be mldrange; that is, Detween "bes~" and "poorestl' val~es, for all properties. Behavior of this type is qhown by Xxamples 39 and 40.

" ~S~7~7 Example 44, which was made using barytes as a filler in place of the ~9 ~hiting used in other exa~ples, shows properties which are signi'icantly better than those for Examples 39 and 40. This occurs because whiti~g S has a specific gravity value of about 2.7, while barytes has a value of about 4.5. ~s a result, at a concen~ra-tion of 72.5~ of filler by weight, the volume~ric fillex level i~ far less for the barytes-containing blend:
Whi~ing slend - 52% filler by vol~me.
Barytes slend - 36% filler by volume.
Thus~ possi~le adverse effec~s which coarser fillers will induce will be far lessened for barytes-filled blends because surface effect~ are related to volume percentage o~ the solids in ~he blend, rather than to a weigh~ per~
15 centage .
E
-The benefits described above which accrue when the type of filler is changed from a coarse type to a ~.iner grade also occur with ethylene-based resins other 20 than those which are modified with vinyl acetate as a comonomer. Table ~I shows the changes which occur when changin~ from coarse to fine fillers for blends which contain 72.5~ of filler and 7.3~ of a process oil, plus a copolymer other than an E~A copolymer. The ethylene/
25 ethyl acrylate blends o~ Comparative Example 19 and Example 45 are identical in all respects, with the sole exception of the filler particle size employed. Also, the ethylene/isobutyl acrylate co~olymer blends of Comparative Example 20 and Example 46 ar~ identical i~
30 all respects, wi~h the sole exception of the filler particle size. Finally, a third set of blends was al50 prepared. The ethylene/methyl me~hacrylate copolymer blends of Comparative Example 21 and Example 47 are alike in all respects, with the sole exception of the filler 35 particle size. In all three of these comparative cases, based on non-E~A ethylene copolymers, the same effects are noted -Fine f iller produces a smooth ex~rudate strand .
-Fine filler produces pellets which pour freely even after standirlg under load.
-The bulk density value is higher when a fine filler is used.
-Smooth pellets made using a finely divided filler hold ~ery lit~le water.

~2 ~ 7~ ~
TABLE ~
~FFECTS OF FILLER PARTICLE SIZE
ON PROPERTIES OF E~HYLENE COPOL~MER
BLXNDS AT 72.5% FILLER( ) Copoly- Visual Pour Bulk Visual Ex. mer~2) ~iller(3)Xxtrudate Rate Density Water No. No. ~ Ratin~__ gO-95F (~/ml) 1evel , . .. _ _ ~
C-l9 ACoarse 4~ 22 (4j 0.85 Wet A Fine 1~ 120,000 0.99 ~ry 10 C-20 ~Coaxse 5 66 (4j 0.~3 Wet 46 B Fin~ 2 120,0Q0 0.99 Dry C-21 CCoar~e 4 15 (4) 0.86 Wet 47 C Fine 1~ 120,000 1.0 Dry (1)A11 blends contain~
Copolymer = 20.2%
"Circosol" 4240 = 7.3%
Fillex = 72.5~
~2)Copolymer numbers are:
(A) Ethylene/ethyl acrylate copolymer, grade DP~A 6182~T, obtained from Union Caxbide Corporation, con~ains about 15~ ethyl acrylate, about 85~ e~hylene, and has a melt index of about 1.5.
(3) Ethylene/isobutyl acrylate copolymer, 20%
isobutyl acrylate, 80~ ethylene, 2.5 MI.
~C) Ethylene/methyl methacrylate copolymer, 18% methyl methacrylate, 82% ethylene, 2.2 MI.
( )Coarse filler i5 FillPr ~8, Table ~III.
Fine filler is Filler ~1, Table ~III.
(4)Coarse filler samples ~ill not flow when pour tested at 90F; hence, all test data for coarse filler only were developed at the much~more-favorable 68-74~F
ambient ç~ndition.

~ 63 ~57~
le 22 The beneficial effec~s of using a ~inely divided filler are not limited to blends which contain 72.5~ filler. Table XVII shows the results secured when blends broadly similar to those of Table XIV are compounded using only 65~ filler. When pxoperties of the blend made for Comparative ~xample C-22 are compared to tho~e of Exa~ples 48 and 49, it is evident that the degree of improvement ls strongly related ~o the par~icle size of the .selected fillex.

The preceding data are for blends made with ethylene copolymers which contain substantial amounts of comonomer. When the comonomer content is in the 18-28~ range, the copolymers tend to be soft, and flow readily. At ranges from lS~ comonomer and below, the polymers tend to be ~ar stiffer. To determine whether the benefits noted earlier wh.ich accrue from the use of fine fillers also apply for blen~s made with sti~fer ~0 resins, additional blends were made and their charac-teristics de~ermined as su.~mari~ed i~ ~ables XVIII and XIX~
All blends were compounded in a laboratory-scale Banbury Mixer for conYenience, as previously de~cribed, and were then processed into sheet for~ in a conven~ional two-roll mill. To mak~ test plaques or sheets, the desired amount o~ blend would be weighed, placed in a laboratory-scale heated press, and pressed (between smooth release sheets of Teflon~-fluorocarbon resin~ in a die of appropriate thic.~ness. For convenience the present die had an opening or 6" X 6'~, was cut from shee~ stock of 58 or 65 mils of thickness, depending on blend density, and was charged in most instances with 63 grams o~ resin blend. This corresponds to 5 lbs.~yd.2 a commonly used sheet weight for automo~ive carp~t use.
A typical cycl was:

64 ~ 5t7;~
TABLE XVII
EFFECTS OF FILI,ER PARTICLE SIZE ON
PROPERTIES OF EVA-BASED BLENDS (1) AT 65% FII,LER
. . . . ~
Visual Pour Bulk Visual Ex. Filler~) Filler (3) Extrudate Ra~e Densi~y Water No. No. Type_ Rati~ 90-35F /ml. Level C-~2 8Coarse ~1250 0.83 Wet 4~ 1Very 1~120, 000 0 . 91 Dry 1 0 Fine 49 6~ine 2~40,000 0.89 Dry ~) All blends contain:
a) EVA ~1 = 25 . 0%
lS b) EVA ~2 = 3 . 5%
c) "Circosol" 4240 - 6 . 5 d) Filler = 65 O 0~
~2) (3)De~ails are given in Table XIII.

` . 65 ~ S7~
TABLE XVIII
EF~ECTS OF FINE FILLER ON THE
PROPERTIES OF B~ DS B~5~D Oi~, EVA HAVING I,OW
VI~rYL ACETATE COMONOMER CONTENT
Filler Visual Pour l~ulk Visual No. & Extrudate Rate Density Water Ex. ( ) ~ ~ 90-95F g/ml Level C -23 8-Coarse "-32200 0 . 70 Wet l-Very Fine1-2105, 000 0 . 70 Damp 10 C-24 8-Coarse 31720 0 . 74 Wet 51 1-Very Fine 2120, 00Q 0 . 80 Damp 52 lwVery Fine 2 5~ / 800 0 . 81 Dry 53 1-Vexy Fine 2610 0 . 78 Dry 15 ( ) Compositions and Blend proper~ies are given in Table XIX.
( )Fille.rs are described in Table XIII.

7'~

TABLE XIX
COMPOSITION AN3 PHYSICAL PROP~RTIES
OF TABLE XVIII BLENDS AND
SELECTED BLENDS OF TABLE XIV
EXAMPLE
C-23 50 ~ 24 51 52 53 C~17 36 _. _ Ingred~ents~
EV~ $1 ~ ~ -- 16.2 1~.2 EU~ ~2 40 40 ~ 28.5 -~ 4.0 4.0 10 ~ #3 ~ .5 ~ __ EV~ #g ~ __ 40 40 _ _~
"Circosol"
~240 5 ~ 5 5 6.5 6.5 7.3 7.3 Filler 55 55 55 55 65 65 72.5 72.5 Pi~ler No. ~ 1 ~ 1 1 1 8 Filler Type C~ar æ Very Ccarse ~ry Very Very Co~rse Very Fine F me Fine Fine Fine Physical ~0 ~:
M~lt In~ex(2) 1.231.06 ~.31 2.08 l.ll 0.73 3.09 1.64 Sp Gr o~
~1~ 1.461~47 1.47 1.46 1.66 1065 1.83 1~83 Tensile 5trength(3) kPa 7030 7790 5240 5030 7790 7240 4760 6070 Elongation, ~(3) 30 40 67 49 26 30 34 46 30 Strip Thi~r.ess, ~15 75 7S 72 73 65 67 59 60 mm 1.90 10~ 1.82 1.85 1.67 1~70 1.50 1.52 ~tiff~ess o~ Strip,(4) g 260 260 15~ 150 200 150 70 6 35 Pour Rate 90-95F 2200 105,0001720 120,G00 54,800 610 122(5) 60,000 ` 67 ~ '7~
(Footnotes for Table XIX) (1) EVA characteristic5 ~1: 25~ vinyl acetate, 75% ethylene, MI = 2.0 !'2: 7.5~ vinyl acetate, 92.5% ethylene, MI = 1.2 ~3: 9.5~ vinyl ace~ate, 90.5~ ethylene t MI = 0.
~4: 12~ vinyl aceta~e, 88% ethylene, MI = 2.5 Fillers are described in Table XIII.
( j De~ermin~d by ASTM Method D 1238 at 190C.
(3) Tensile strength and elongation measurements made on Instron Tes~er using AST~ ~ethod D 1708 a~ cross-head speed of 2 in. (5.1 cm. )/min. Samples are 0u876 in (2.23 cm.) X 0.187 in (0.47 cm.) in size, at strip thickness shown in table.
( ) Stifness of strip measured by placing a l in. X
6 in. (2.54 cm. X 15.2 cm.) strip on a platform scale and measuring the force required to make the ends of the test strip meet at room temperature.
(S) ~etermined at 68-74F--not determined at 90~95F, as blocking o~ the sample is predictabl~.

`: 68 ~ Z~
(1) Place a Teflon3 shee~ on lowex press platen or on top of a smooth ste~l baseplate if the platen is not truly smoo~h~
(2) Place ~n 8" X 10" die plate t6" X 6"
5 openiIlg) atop the Tef lon~ sheet .
(3) Pu~ 63 g. of resin in the cavity. (1-2 grams surplus may be needed as some blend may ooze out duxing pres 5 ing~ .
(4) Place a Teflon~ fluorocarbon sheet atop 10 the resin. Add a smooth steel upper plate if th platen is nol: truly smoo~h.
t5) Heat the press to 175C.
(6) When the press reaches 175C., slowly pump the press cl4sed ~o a total pxessure of abou~
12, 500 pounds ~150 psi, approximately) .
17) After 2 mirlutes, raise tAe ram pressure to 50 , 000 pounds (~00 psi , approximately), and hold the pressure and temperature constant or about 1 minute.
(8) Shut off heat and cool press to ambient 20 t:emperature with ram in closed posi~ioI10 (9) Release pressure, remove qample, a~d cut ko appropriate shape for further testing.
tlO~ Age ~amples overnight a~ 50~i RH and 72~.

In evalua~ing highly filled blends, grea~
care and good technique must be used in making all samples, as surface imperfections will cause ~ide variations in measurements o~ tensile strength and elongation.
Blends of C-23 and Example 50 are identical witn th~ exception of fineness of filler. Both are based on a copolymer which oontalns only 7.5~ vinyl ~cetate comonomex, and thus are quite stlff and hard.
By contrast, E~A #1 with 25% vinyl ace~ate con~ent, used as the principal resin in the blends of Table XIV, is flexible and will produce flexible blends as seen in Table XX.
TASLE XX
stif~neS9~1) Hardness(2) EVA #1 20.7 36 EVA ~2 96.5 44 (l)MPa, method of ASTM D 747; psi values are 3,000 & 14,000 respectively.
( )Shore D hardness, ASTM D ~706.
Examination o~ Table XV~II shows once again that the use of a finely divided ~iller yields blends wltich will be smcother to the eye and to the touch and ~hus will tend to hold less water and to have a far superior flow rate as measured by the pour rate tes~.
Examples 52 and 53 illus~rate blend~ at 65~
filler loadin~, between the earlier shown 55% and 72.5%
filler contents. Since a ~ine filler was used, once again the pellets a~ained were smoo~h and dry. The pour ratlng for Example 52 is excell~nt~ that for Example 53 is marginal. Xt is believed that the di~ferences are due to use of copolymers having 3S different ~inyl ac ta~e contents. The diffexences might also indicate ~hat the pour rate test t although a useul screening t~st t may not be ~o precise as might be desired.
Repetitive tests are desirable 7 n all cases to be certain ~ ~57 ~
tha~ error is no~ introduced in the long chain:
weighing ~ premixing - Banbury blending - extrusion -chopping - and final tes~ing of pellets.
Discussion~ to this point have stressed only the effects of fine filler on physical ex~rudate proper-ties such as smoothness, tendency to hold water, relative pour rate~, e~c. Those who wish to secure t~ese benefits mu~t, of course, plan to investigate o~her, unrelated changes to the properties of blends which might be caused by changing the type of filler. As a suide to compounders,Table XIX shows for several pairs of blends from Tables XIV and ~ II th~ types of changes which may be expected in o~her properties of interest. Generally, these-changes are relatively small and are beneficial.
~a) ~elt Index - In all cases r use of a finer fill2r decreased the melt index of the blend. Thus, the use of finer filler increases blend ~îscosity.
However, the changes which occur are relatively small and will probably be acceptable for most end user5~
In the case of Examples 52 and 53, the melt index change noted reflects the lower melt index for EVA ~3, vs. ~hat for EVA #2.
(b) Blend Specific Gravity - This property is a~fected only by filler loading--no~ by the particle ~ize of ~iller or change in type of EVA resin selected.
(c) Tensile Strength and Elongation - In most cases, use of a finer filler will enhance these proper-ties by lO to 20%, although this did not occux for Example 51 ~s. C-24. This could reflect lack o sufficient mixing for sample Example 51, or could reflect an error during the tensile test procedure. In any event, the bulk of our experience indicates that it is desirabl~ to use a fine ~iller where optimum tensile strength and elongation are needed. Con~ersely, such minor changes are probably not ~ommercially impor~ant to ~os~ us~xs.

c 7 1 ~ d) S~i~fness and Strip ~hickness - ~11 test strips ~nade were based on constan~ weigh~ per unit area, rather ~han constant volume per unit area. Thus, all comparisc)ns presented mus~ be judged on a pair 5 basls. When this is done, it is evidPnt tha~ change o:E ~iller par~icle size is far less important than is filler amoun~ F~lr~her, choice of resin ls an importank variable, as s~own by comE: arison o~ Example S2 with Example 53-~high r V~c level results in a less stiff 10 blend, despite he use of a lewer mel~ ~ ndex copolymer.
(e) Pour Rate - The significan~ irnprov man~
produced by u~e of finer filler has been discu~sed in detail abo~e . The comparisc: ns giY@n abo~re pro~7ide strong reasc~ns for a ::ompounder ~o employ an ul~rafine 15 fill2r--but a change of ~his type is of necessity accc~anied by adverse ~f fec~s . ~he amount of energy input needed to make finer and finex filler grade is a significarlt cost item~ In addi~ion, grinding and classi~iciation e~Euipment output falls as finer par~icle ~o sizes are produced, and the ultimate customer must o~ course bear the inves~ment burden required. 'Xhus, or every product the compaunder mus~ balance the co~ts of a ~iner ~iller Ye~sus the benefits that will accrue. Therefore, the "best" chsice of filler fine-25 ness must ~rary from user to user from applica~ion toapplica~ion.
This application is a division of copending application Serial No. 339 920, filed 1979 November 15.

3~

Claims (4)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. Extrudable thermoplastic composition consisting essentially of (a) from about 5 to about 50 parts by weight of at least one copolymer of ethylene with at least one comonomer selected from the group consisting of unsaturated mono- or dicarboxy-lic acids of 3 to 5 carbon atoms and mono esters of said dicarboxylic acids, the ethylene content of said copolymer being at least about 60% by weight, the comonomer content of said copolymer being from an amount sufficient to provide the desired oil compatibility and blend elongation to about 40% by weight, and the melt index of said copolymer being from about 0.1 to about 150; (b) from about 2 to about 15 parts by weight of processing oil; and (e) from about 50 to about 90 parts by weight of filler, said compositions being in a form selected from the group consisting of a sound-deadening sheet and a backside coating on a carpet.

2. The composition of Claim 1 in the form of a sound-deadening sheet.

3. The composition of Claim 1 in the form of a backside coating on a carpet.

4. The composition of Claim 1 in the form of a backside coating on an automotive carpet.